Optimization of hematite nanoparticles from natural ore as novel imaging agents: A Green Chemistry approach

Abstract

In this research, we propose an environmentally friendly method for producing hematite nanoparticles (H‐NPs) from natural hematite ore, focusing on their application as efficient contrast agents in x‐ray and computed tomography (CT) imaging for medical purposes. The process involves the reduction of iron oxide within the ore to attain the desired hematite phase, crucial for synthesizing H‐NPs. To ensure sustainability, we adopted a Green Chemistry approach, utilizing a combination of carbon soot and limestone for the purification process, thereby achieving eco‐conscious production. The produced H‐NPs were thoroughly characterized using various analytical techniques, such as x‐ray fluorescence (XRF), x‐ray diffraction (XRD), Fourier transmission infrared spectroscopy (FT‐IR), and FESEM‐EDX (field emission scanning electron microscopy‐energy‐dispersive x‐ray spectroscopy). XRD analysis confirmed the crystalline rhombohedral hexagonal lattice structure, while FT‐IR spectra indicated the presence of characteristic Fe–O stretching modes in line with the expected molecular composition. FESEM‐EDX imaging unveiled agglomerated particles, ranging in size from 54.6 to 149.9 nm for iron ore and 22 nm for H‐NPs. These particles were primarily composed of iron (Fe) and oxygen (O). The magnetic properties of the H‐NPs were investigated through vibrating sample magnetometer (VSM) studies, highlighting their distinct ferromagnetic behavior. Of particular significance, the H‐NPs demonstrated exceptional performance as contrast agents in both x‐ray and CT imaging. Even at minimal concentrations, they exhibited remarkable x‐ray absorption capabilities. CT scans further validated their exceptional absorptive capacity. These findings emphasize the potential of H‐NPs as valuable assets in medical imaging, serving as sustainable tools for enhanced diagnostic applications. The study showcases an eco‐conscious approach to harnessing natural resources, paving the way for a greener and more effective utilization of H‐NPs in the medical imaging landscape.